U.S.-born citizen-children of undocumented or illegal immigrants are often the unintended victims of deportation policies. When deported, parents must make critical decisions: to take their citizen-children with them or leave them behind in the care of others. But, what happens to the psychosocial functioning of citizen-children who have left the U.S. or remained behind after immigration-enforcement actions are taken against their parents? To begin answering these questions, this R21 will (a) develop the methods and test their feasibility in recruiting, interviewing, and following children affected by their parents' deportation; and (b) collect preliminary data to develop detailed psychological and social profiles of how children fare during a six- month period as they adjust to their circumstances. A team of researchers from the U.S. and Mexico, will conduct in-depth interviews and clinical assessments of 60 children between 10 and 12 years of age spread across three groups: 20 who accompanied their deported parents to Mexico; 20 who remained in the U.S. when parents were deported; and a comparison group of 20 citizen-children whose undocumented parents are not being deported at the time. The developmental-exploratory aims are to: I. Develop procedures for a bi-national (U.S.-Mexico) exploratory, longitudinal project on citizen-children. II. Develop and test in-depth interviews and clinical measures to be used at 2 data-collection points. III. Compare the experiences and clinical profiles of citizen-children in all three groups. Findings and experience gained through this project will set the basis for a rigorous R01 application that will, together with the present project, inform developmental science and influence national policy. This project aligns with NICHD's mission that all children have the chance to achieve their full potential for healthy and productive lives, free from disease or disability, and to ensure the health, productivity, independence, and well-being of all people. Specifically, NICHD's Demographic and Behavioral Sciences Branch urges exploration of why people migrate, how it reshapes them, and how movement affects children's behavior problems.